1. Field of the Invention
This invention relates to catheters and more particularly to a catheter for injecting an agent at specified positions of the heart muscle (myocardium).
2. Description of Related Art
In the past devices have been used for minimally invasive techniques to access the heart, veins and arteries immediately adjacent by inserting catheters into the larger veins and arteries of the neck, arm and leg. These devices are used for balloon angioplasty, laser surgery, to make endoscopic observations of valves, plaque buildup and other cardiac conditions, or to take pressure and temperature readings in various chambers of the heart and in the nearby veins and arteries. Even microsurgery can be performed by these minimally invasive techniques. Dyes, radioactive materials, radiopaque contrast materials or other substances can be added to the heart by such devices to aid in x-rays, CAT scans or other observations and measurements of the heart. However there is no currently available means for accurate patterned delivery of gene injection therapies or other injections into the myocardium of the various chambers of the heart or into the veins and arteries nearby.
The invention is for minimally invasive delivery of agents for the treatment of medical conditions in the heart or adjacent veins and arteries where precision injection of genes or other agents is required in the treatment of the patient.
A catheter is inserted into the patient""s veins or arteries of the arm, leg, or neck and threaded to the heart or other area to be injected with a medicant.
The catheter firmly presses against the tissue to be injected. The pressure of the catheter against the tissue to be treated may be by a fluid pressure in the catheter, by wires in the catheter or by a catheter with a material shaping to a memory position. The catheter has at least one aperture for a needle to be inserted therethrough or withdrawn therefrom to inject a medicant into tissue adjacent the apertures of the catheter. The needle can be on the end of a stylet which is mechanically sprung to eject from an aperture when the needle point is aligned with an aperture of the catheter. A plunger may be depressed to push a medicant of a known dose into the tissue adjacent the aperture or a pump may be used to inject the medicant. Alternatively a needle can be forced through an aperture by fluid pressure within the catheter acting on a mechanism to insert the needle into the tissue to be injected. The same fluid pressure may be used to pump a known amount of a medicant through the needle, or as above a plunger or a pump may be used.
It is an object of the invention to minimally invasively inject agents into or through the endocardium or myocardium.
It is an object of the invention to provide a precision pattern of injections in the endocardium or myocardium.
It is an object of the invention to provide gene therapy or introduce other therapeutic agents to the heart.
It is an object of the invention to provide a catheter for injecting a medicant into or through the interior walls of the cardiovascular system such as veins, arteries and chambers of the heart.